import os

from flask import Flask
from markupsafe import escape


def create_app(test_config=None):
    # create and configure the app
    app = Flask(__name__, instance_relative_config=True)
    app.config.from_mapping(
        SECRET_KEY='dev',
        DATABASE=os.path.join(app.instance_path, 'flaskr.sqlite'),
    )

    if test_config is None:
        # load the instance config, if it exists, when not testing
        app.config.from_pyfile('config.py', silent=True)
    else:
        # load the test config if passed in
        app.config.from_mapping(test_config)

    # ensure the instance folder exists
    try:
        os.makedirs(app.instance_path)
    except OSError:
        pass

    # a simple page that says hello
    @app.route('/hello/<name>')
    def hello(name):
        app.logger.debug('A value for debugging')
        app.logger.warning('A warning occurred (%d apples)', 42)
        app.logger.error('An error occurred')
        return f"Hello, {escape(name)}!"

    @app.route('/path/<path:subpath>')
    def show_subpath(subpath):
        # show the subpath after /path/
        return f'Subpath {escape(subpath)}'

    from . import db
    db.init_app(app)

    from . import auth
    app.register_blueprint(auth.bp)

    from . import blog
    app.register_blueprint(blog.bp)
    app.add_url_rule('/', endpoint='index')

    return app



